Program Director: Montgomery, Robert R. Core B Leader: Bellissimo, Daniel B. CORE B: VWF PHENOTYPING ANDMOLECULAR ANALYSIS CORE A. Description of Core and Relationship to Component Projects Core B is the VWF Phenotyping and Molecular Analysis Core. This Core is composed of the Hemostasis Reference Laboratory and the Molecular Diagnostics Laboratories at The Blood Center of Southeastern Wisconsin. The Hemostasis Reference Laboratory will be responsible for full VWF laboratory phenotyping. The Molecular Diagnostics Laboratory will be responsible for DNA sequencing of the VWF gene, VWF gene linkage analysis and DNA sequencing of non-linked modifier genes or causes that contribute to an abnormal VWF phenotype. The Core Leader, Dr. Bellissimo, is board certified in Clinical Molecular Genetics and has extensive experience directing a clinical molecular diagnostics laboratory. He routinely reviews DNA sequencing data for clinical VWF sequencing assays for exons 18-20, exons 23-24 and exon 28. The Core Co-Leader, Dr. Friedman, is the medical director of the Hemostasis Reference Laboratory. He has extensive experience running a clinical hemostasis laboratory and is an expert in the treatment and diagnosis of von Willebrand disease and in reviewing VWF laboratory results. Von Willebrand factor testing is technically complex. We feel that it is critically important that a routine clinical lab be the